Diagnosis of eye diseases depends critically on imaging of the retina and its supporting vasculature, including the choroidal blood vessels, which must be viewed through the sensory retina. We propose to determine whether the diagnostic capabilities of one of the newest retinal imaging instruments, the scanning laser ophthalmoscope (SLO), can be enhanced by the use of near-infrared, wavelength-tunable laser source. Our preliminary experiments in combining the SLO with a tunable Ti:sapphire laser indicate that careful wavelength tuning should make it possible to better characterize sub-retinal structures such as choroidal vessels - in particular new vessels indicative of eye disease - in spite of the overlying retinal layers which obscure this view at present. The research plan would involve interfacing a TI: sapphire laser, continuously tunable over the 700-950 nm range, with a scanning laser ophthalmoscope and taking images of the ocular fundus over that range. The images would be analyzed for the presence of vasculature and other detail not observed by fixed- wavelength imaging systems. If clinically significant results were obtained, the development of a commercial laser source would proceed in a Phase II program, and would be the key to a new generation of diagnostic instruments.